Ad-hoc CRON jobs from a console application with Hangfire

Program.cs

using Hangfire;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddHangfire(configuration => configuration
    .UseSimpleAssemblyNameTypeSerializer()
    .UseRecommendedSerializerSettings()
    .UseInMemoryStorage());

builder.Services.AddHangfireServer();

var app = builder.Build();

// host dashboard at "/"
app.MapHangfireDashboard("");

await app.StartAsync();

var cts = new CancellationTokenSource();
var ct = cts.Token;
while (!ct.IsCancellationRequested)
{
    Console.WriteLine("Enter a command:");
    var command = Console.ReadLine();
    switch (command)
    {
        case "?":
            Console.WriteLine("Commands:");
            Console.WriteLine("  ? - show this help");
            Console.WriteLine("  q - quit");
            Console.WriteLine("  s - schedule a job");
            Console.WriteLine("  r - remove a job");
            break;
        default:
            Console.WriteLine("Unknown command: " + command);
            goto case "?";
        case "q": 
            cts.Cancel();
            break;
        case "s":
        {
            Console.WriteLine("Enter a schedule:");
            var schedule = Console.ReadLine();
            Console.WriteLine("Enter an ID:");
            var id = Console.ReadLine();
            RecurringJob.AddOrUpdate(
                id,
                () => Console.WriteLine("Ahoy!"), 
                schedule
            );
            break;
        }
        case "r":
        {
            Console.WriteLine("Enter an ID:");
            var id = Console.ReadLine();
            RecurringJob.RemoveIfExists(id);
            break;
        }
    }
}

await app.StopAsync();